Effects of hardening and plant age on development of resistance to cottony snow mold (Coprinus psychromorbidus) in winter wheat under controlled conditions

1987 ◽  
Vol 65 (6) ◽  
pp. 1152-1156 ◽  
Author(s):  
D. A. Gaudet ◽  
T. H. H. Chen
Keyword(s):  
Winter Wheat ◽  
Plant Age ◽  
Day Length ◽  
Minor Role ◽  
Freezing Resistance ◽  
Snow Mold ◽  
Wheat Seedlings ◽  
Development Of Resistance ◽  
Mold Resistance ◽  
A Minor

The development of resistance in winter-wheat seedlings to the cottony snow mold pathogen, Coprinus psychromorbidus Redhead et Traquair, was studied under controlled-environment conditions. Resistance was measured by the percentage of inoculated plants surviving after incubation at −3 °C for 8–12 weeks. The number of weeks of prehardening growth prior to inoculation, fresh weight, LT50, and tiller number were positively correlated with resistance to C. psychromorbidus. Prehardening temperatures of 7 and 15 °C favored development of snow mold resistance compared with 2 °C, but the LT50 (50% killing temperature) values of uninoculated plants were not significantly different. After 1 and 2.5 weeks growth at 20 °C, plants hardened at 2 °C and 12-h day length gradually increased in resistance to snow mold from 1 to 15 weeks of hardening. Development of resistance to C. psychromorbidus in winter wheat was most influenced by the amount of prehardening growth, and the development of freezing resistance played a minor role in disease resistance development. This form of resistance, which develops with increasing plant age, appeared to reduce the rate of infection and disease development by C. psychromorbidus.

Effect of plant age on water content in crowns of fall rye and winter wheat cultivars differing in snow mold resistance

2001 ◽  
Vol 81 (3) ◽  
pp. 541-550 ◽  
Author(s):  
D. A. Gaudet ◽  
A. Laroche ◽  
B. Puchalski
Keyword(s):  
Winter Wheat ◽  
Water Content ◽  
Developmental State ◽  
Early Spring ◽  
Plant Age ◽  
Wheat Cultivars ◽  
Snow Mold ◽  
Winter Wheat Cultivars ◽  
Controlled Environments ◽  
Mold Resistance

Resistance to snow molds in winter wheat increases with plant age, and older plants express higher levels of resistance than young plants. Experiments were conducted to study the effect of plant age on percent crown water content (%CWC) and dry weights in fall rye and winter wheat cultivars grown under controlled environments and in the field at Lethbridge, AB. Under controlled environments, the oldest (6 wk of pre-hardening growth at 20°C) treatments accumulated the greatest dry weights following exposure of plants to 1 to 6 wk hardening conditions at 2°C, compared with younger (1 to 4 wk pre-hardening growth) treatments. Exposure of plants to hardening temperatures had the greatest effect on %CWC values, which decreased, gradually, from 82–89% (4.95–8.67 g H2O g–1 DW) in unhardened treatments to 67–72% (2.05–2.65 g H2O g–1 DW) in plants receiving the 6 wk pre-hardening and 6 wk hardening growth. However, the oldest treatments (4 to 6 wk pre-hardening growth) always exhibited the lowest %CWC values among all hardening treatments. The %CWC in the oldest (6 wk) unhardened plants was also lower ([Formula: see text] = 80.8% or 4.24 g H2O g–1 DW) than in the youngest (1wk) unhardened plants ([Formula: see text] = 91.2% or 11.31 g H2O g–1 DW ), demonstrating that water loss occurs in older plants in the absence of low hardening temperatures. In a field study at Lethbridge during the autumn, winter, and early spring of 1997–1998 and 1998–1999, different seeding dates were employed to obtain plants differing in age and developmental state. The %CWC in early-seeded treatments was lower during the autumn, and remained lower in early spring, compared with later seeded cultivars. The %CWC in crowns was negatively associated with the snow mold resistance rating of a fall rye and five winter wheat cultivars under controlled environment conditions, and among a fall rye and 13 winter wheat cultivars in the field; the highest correlation values in the field were observed from mid-November to mid-March during 1997–1998 (r = –0.84), and 1998–1999 (r = – 0.76). These results indicate that the type of snow mold resistance that increases with plant age is related to the accumulation of crown dry matter and the ability of wheat and rye plants to lose crown water in response to both extended growth at warm temperatures and hardening at low, above freezing temperatures. Key words: Carbohydrates, fructans, low temperature basidiomycete, Coprinus psychromorbidus

Effect of freezing resistance and low-temperature stress on development of cottony snow mold (Coprinus psychromorbidus) in winter wheat

1988 ◽  
Vol 66 (8) ◽  
pp. 1610-1615 ◽  
Author(s):  
D. A. Gaudet ◽  
T. H. H. Chen
Keyword(s):  
Low Temperature ◽  
Winter Wheat ◽  
Temperature Stress ◽  
Negative Relationship ◽  
Triticum Aestivum L ◽  
Low Temperature Stress ◽  
Freezing Resistance ◽  
Snow Mold ◽  
Canadian Prairies ◽  
Mold Resistance

The relationship between snow mold resistance and freezing resistance was studied under controlled-environment conditions, using winter wheat (Triticum aestivum L. em. Thell) cultivars varying in freezing resistance and resistance to cottony snow mold (Coprinus psychromorbidus Redhead & Traquair). Cultivars varying in freezing resistance were equally susceptible to C. psychromorbidus. There existed a negative relationship between snow mold resistance and freezing resistance. Sublethal, subzero freezing temperatures between −3 and −12 °C predisposed the winter wheat cultivar 'Winalta' to increased damage by C. psychromorbidus. A synergistic effect resulting in increased mortality was observed when winter wheat plants received a combination of low-temperature stress and inoculation with C. psychromorbidus. In hardened winter wheat plants, sublethal levels of snow mold damage following 6 weeks incubation with C. psychromorbidus resulted in a reduction in freezing resistance or LT50 (50% killing temperature) of approximately 7 °C compared with the noninoculated controls. The possible role of low-temperature stress on the susceptibility of winter wheats to C. psychromorbidus and of snow mold infection on the retention of freezing resistance in winter wheats during winter in the central and northern Canadian prairies is discussed.

Screening winter wheat for resistance to cottony snow mold under controlled conditions

1991 ◽  
Vol 71 (4) ◽  
pp. 957-965 ◽  
Author(s):  
D. A. Gaudet ◽  
G. C. Kozub
Keyword(s):  
Winter Wheat ◽  
Screening Test ◽  
Wheat Cultivars ◽  
Freezing Resistance ◽  
Snow Mold ◽  
Percent Survival ◽  
Controlled Conditions ◽  
Percentage Survival ◽  
Winter Wheat Cultivars ◽  
Mold Resistance

A screening test was developed to determine the level of resistance of winter wheat to cottony snow mold (Coprinus psychromorbidus) under controlled conditions. The best separation in disease reaction among cultivars occurred following prehardening growth for 1 wk at 20 °C, hardening at 2 °C for 3 wk, and inoculation and incubation with the cottony snow mold pathogen at −3 °C for 9 wk. Percent survival was determined following a 3-wk recovery in the greenhouse. Extending prehardening growth to 6 wk increased the overall level of survival, but reduced the ability of the screening test to differentiate among cultivars. In general, there was a decrease in the percent survival in the 3-wk prehardening growth treatment compared with the 1- and 6-wk treatments. Percent survival and the ability to differentiate among cultivars decreased with increasing length of incubation with the cottony snow mold pathogen at −3 °C. The snow mold resistance and LT50 temperatures of 24 winter wheat cultivars, Kodiak fall rye and winter triticale were determined. Winter wheat cultivars CI14106, PI186822, Sprague, M81-8661, Münstertaler, and PI172582 exhibited high percentage survival following inoculation with cottony snow mold, but all cultivars exhibited low levels of freezing resistance except Münstertaler, which exhibited an intermediate level of freezing resistance. Key words: Freezing resistance, winter wheat

scholarly journals Effect of biostimulants on cold resistance and productivity formation in winter rapeseed and winter wheat

2018 ◽  
Vol 57 (1) ◽  
pp. 71-83 ◽  
Author(s):  
V. Gavelienė ◽  
L. Pakalniškytė ◽  
L. Novickienė ◽  
L. Balčiauskas
Keyword(s):  
Winter Wheat ◽  
Free Amino ◽  
Field Experiments ◽  
Cold Resistance ◽  
Growth Parameters ◽  
Freezing Resistance ◽  
Wheat Seedlings ◽  
Natural Field ◽  
Winter Rapeseed ◽  
Growth Development

AbstractThe aim of the study was to investigate the effects of biostimulants on the resistance to freezing under laboratory-controlled cold conditions and on the growth, development, overwintering and productivity of winter rapeseed and winter wheat in natural field experiments. The effect of free amino acids, macroelements and microelements that contain biostimulants Ruter AA, Terra Sorb and Razormin was tested on cultivars of rapeseed, ‘Hornet H’, and winter wheat, ‘Skagen’ and ‘Kovas’, applying morphometrical methods. We found that biostimulants applied to rapeseed at BBCH 13–14 stage and to wheat at BBCH 14–15 stage under controlled cold stress conditions increased the freezing tolerance of seedlings. Biostimulants more actively increased the freezing resistance of rapeseed seedlings at –5°C compared to that of wheat seedlings. The temperature of –7°C was mortal to rape seedlings, while the resistance of wheat seedlings increased under the influence of the tested biostimulants compared to that of the control seedlings. In natural field experiments, these biostimulants produced a significant effect on plant growth in autumn, acclimation to the cold, plant overwintering, vegetation renewal and, due to this, formation of productivity elements. The effects of Razormin (200 mL/ha), Terra Sorb (2 L/ha) and Ruter AA (1 L/ha) were significantly higher on growth parameters of winter wheat compared to the productivity of winter rapeseed.

Development of resistance to Microdochium nivale in winter wheat during autumn and decline of the resistance under snow

1994 ◽  
Vol 72 (8) ◽  
pp. 1211-1215 ◽  
Author(s):  
T. Nakajima ◽  
J. Abe
Keyword(s):  
Winter Wheat ◽  
Snow Cover ◽  
Triticum Aestivum L ◽  
Microdochium Nivale ◽  
Snow Mold ◽  
Development Of Resistance ◽  
Rate Of Decline ◽  
Food Reserves ◽  
Fusarium Nivale ◽  
Accumulated Degree Days

The effect of autumn climate on the development of resistance to pink snow mold (Microdochium nivale) in winter wheat was estimated in mid-December. Changes in resistance over time under snow cover were also determined. Resistance in December was closely correlated with the accumulated degree-days above 0 °C from sowing. The number of days of incubation at which 50% of the plants are killed (LI50) was lowest in the cool autumn in 1988 and highest in the warm autumn in 1989. Temperatures below 5 °C were also required for expression of resistance. Differences in LI50 between resistant and susceptible cultivars were most apparent in late autumn. Continuous snow cover was found to reduce resistance to pink snow mold. The rate of decline of the resistance in cv. Nanbukomugi during the winters under snow was lower than in cv. PI 173438 and cv. Kitakamikomugi. The resistance to pink snow mold was correlated with the amount of etiolated growth at 25 °C. This indicates that exhaustion of food reserves during prolonged snow cover predisposed wheat plants to snow mold diseases. Key words: pink snow mold, Fusarium nivale, Monographella nivalis, resistance progressive and degressive curves, Triticum aestivum L., field test.

scholarly journals Mapping QTL conferring speckled snow mold resistance in winter wheat (Triticum aestivum L.)

2020 ◽  
Vol 70 (2) ◽  
pp. 246-252
Author(s):  
Zenta Nishio ◽  
Norio Iriki ◽  
Miwako Ito ◽  
Tadashi Tabiki ◽  
Timothy Murray
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Snow Mold ◽  
Mapping Qtl ◽  
Mold Resistance

The Effect of Path Length and Display Size on Memory for Spatial Information

2012 ◽  
Vol 59 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay
Keyword(s):  
Path Length ◽  
Potential Role ◽  
Spatial Information ◽  
Recall Performance ◽  
Minor Role ◽  
Length Effect ◽  
Serial Memory ◽  
Fixed Reference ◽  
A Minor

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

Use of Different Tissue Thromboplastins in the Control of Anticoagulant-Therapy

1958 ◽  
Vol 02 (05/06) ◽  
pp. 462-480 ◽  
Author(s):  
Marc Verstraete ◽  
Patricia A. Clark ◽  
Irving S. Wright
Keyword(s):  
Prothrombin Time ◽  
Anticoagulant Therapy ◽  
Factor Vii ◽  
Rabbit Brain ◽  
Minor Role ◽  
Rabbit Lung ◽  
Coagulation Mechanism ◽  
Time Test ◽  
The One ◽  
A Minor

SummaryAn analysis of the results of prothrombin time tests with different types of thromboplastins sheds some light on the problem why the administration of coumarin is difficult to standardize in different centers. Our present ideas on the subject, based on experimental data may be summarized as follows.Several factors of the clotting mechanism are influenced by coumarin derivatives. The action of some of these factors is by-passed in the 1-stage prothrombin time test. The decrease of the prothrombin and factor VII levels may be evaluated in the 1-stage prothrombin time determination (Quick-test). The prolongation of the prothrombin times are, however, predominantly due to the decrease of factor VII activity, the prothrombin content remaining around 50 per cent of normal during an adequate anticoagulant therapy. It is unlikely that this degree of depression of prothrombin is of major significance in interfering with the coagulation mechanism in the protection against thromboembolism. It may, however, play a minor role, which has yet to be evaluated quantitatively. An exact evaluation of factor VII is, therefore, important for the guidance of anticoagulant therapy and the method of choice is the one which is most sensitive to changes in factor VII concentration. The 1-stage prothrombin time test with a rabbit lung thromboplastin seems the most suitable method because rabbit brain preparations exhibit a factor VII-like activity that is not present in rabbit lung preparations.

Sign in / Sign up

Export Citation Format

Share Document